The A122 (Lower Thames Crossing) Development Consent (Amendment) Order 2025
This Order amends the A122 (Lower Thames Crossing) Development Consent Order 2025 following an application for a non-material change concerning environmental mitigation measures for the Epping Forest Special Area of Conservation (SAC).
The amendment specifically replaces a commitment in the Code of Construction Practice register regarding air quality effects, mandating the implementation of appropriate technology to enable a 60mph westbound speed limit enforcement zone on the M25 between junctions 26 and 27, coupled with detailed monitoring, reporting, and appropriate funding arrangements to prevent Adverse Effect on Integrity (AEoI) from nitrogen deposition.
Arguments For
The amendment clarifies and strengthens environmental mitigation commitments necessary to prevent Adverse Effect on Integrity (AEoI) on the Epping Forest Special Area of Conservation (SAC) due to traffic emissions from the new crossing.
Implementing a potential 60mph westbound speed limit between M25 junctions 26 and 27, supported by necessary technology and funding, directly addresses nitrogen deposition concerns.
Establishing a defined monitoring period (minimum 4 years post-operation) and required annual reporting ensures ongoing accountability and responsiveness to environmental impact data by involving Natural England in consultations.
Arguments Against
Imposing a mandatory 60mph speed limit and associated enforcement costs may increase operational expenditure and potentially disrupt traffic flow on the M25 motorway.
Requiring monitoring commencing six months after construction begins and lasting for years post-operation places a significant long-term administrative and financial burden on National Highways and enforcement authorities.
The provision allowing the Secretary of State to remove the speed limit requirement based on consultation, even if initial monitoring suggests continued risk, could introduce regulatory uncertainty regarding long-term environmental protection.
An application has been made under paragraph 2 of Schedule 6 to the Planning Act 2008 to the Secretary of State in accordance with the Infrastructure Planning (Changes to, and Revocation of, Development Consent Orders) Regulations 2011 for a non-material change to the A122 (Lower Thames Crossing) Development Consent Order 2025.
An application was submitted to the Secretary of State requesting a non-material change to the existing Development Consent Order (DCO) for the A122 Lower Thames Crossing project.
This process follows specific regulations established under the Planning Act 2008 for managing minor alterations to major infrastructure consents.
The Secretary of State, having considered the application and the responses to the publicity and consultation carried out in accordance with regulations 6 and 7 of the Infrastructure Planning (Changes to, and Revocation of, Development Consent Orders) Regulations 2011, has decided to make this Order amending the A122 (Lower Thames Crossing) Development Consent Order 2025.
The Secretary of State reviewed the application and all feedback received during required public consultation periods.
Based on this consideration, the decision was made to formally issue this new Order, which enacts the specified amendments to the original 2025 Development Consent Order.
The Secretary of State in exercise of the powers conferred by paragraph 2 of Schedule 6 to the Planning Act 2008, makes the following Order.
The Secretary of State is issuing this formal Order using the legal authority granted under the Planning Act 2008 to modify the existing development consent.
- Citation and commencement
This Order may be cited as the A122 (Lower Thames Crossing) Development Consent (Amendment) Order 2025 and comes into force on 5th November 2025.
This legislation is officially named the A122 (Lower Thames Crossing) Development Consent (Amendment) Order 2025.
It officially becomes active and enforceable on November 5, 2025.
- Amendments to the A122 (Lower Thames Crossing) Development Consent Order 2025
(1) The A122 (Lower Thames Crossing) Development Consent Order 2025 is amended as follows.
(2) The A122 (Lower Thames Crossing) Development Consent Order 2025 is amended as follows.
In paragraph 26(4) (amendments to be made to the Code of Construction Practice and the REAC) of Part 3 (amendments to be made to the control documents) of Schedule 2, in the first row (REAC ref no. “HR013”) of Table 2, for the text in the fifth column (commitment) substitute—
“Appropriate technology and infrastructure would be employed to enable, if required, the enforcement authority to enforce a 60mph speed limit in a westbound direction between junctions 26 and 27 of the M25 to ensure that there is no Adverse Effect on Integrity (“AEoI”) on Epping Forest SAC as a consequence of traffic emissions leading to increases in nitrogen deposition, NOx and/or NH3. Reasonable and appropriate funding would be provided to the highway and enforcement authority to set a 60mph limit and to undertake enforcement activities. Monitoring should commence no later than 6 months after commencement of construction of the A122 Lower Thames Crossing and remain in place for a minimum period of 4 years following commencement of operation to monitor levels of NOx, NO2 and NH3 (which can be used to determine the vehicle emission related nitrogen deposition) compared to pre-operational values. Annual reporting should be undertaken and include a review of relevant evidence, such as monitoring, traffic data and regional pollution in consultation with Natural England. The 60pmh speed limit measures are to be put in place from the commencement of operation. The Secretary of State may determine, upon receipt of a written request from National Highways that has been informed and agreed through consultation with Natural England, that such measures no longer remain required at or after the point of commencement of operation to prevent an AEoI (on the basis of pre-operation monitoring and any additional assessment undertaken by National Highways). If the outcome from monitoring and updated modelling shows relevant increases in nitrogen deposition, and/or NOx and/or NH3 which would lead to an AEoI then that speed limit control and enforcement must be in place, unless otherwise agreed with Natural England.”.
This article details the specific modification made to the primary Development Consent Order (DCO) from 2025.
It replaces a commitment recorded under reference 'HR013' in the Code of Construction Practice, which relates to controlling air quality impacts.
The new commitment requires measures to facilitate a 60mph westbound speed limit on the M25 near junctions 26 and 27 to protect the Epping Forest SAC from harmful nitrogen-based pollution (NOx, NH3, and deposition).
This plan includes providing necessary funding for enforcement, starting monitoring within six months of construction commencement, and continuing monitoring for at least four years after the crossing opens, with annual reviews involving Natural England.
Signed by authority of the Secretary of State for Transport Kayla Marks Head of the Transport and Works Act Orders Unit 4th November 2025 Department for Transport
This section verifies the enactment of the Order, signed by an authorized official from the Department for Transport on November 4, 2025, confirming its official status prior to the commencement date.
Explanatory Note (This note is not part of the Order)
This Order amends the A122 (Lower Thames Crossing) Development Consent Order 2025 (“the 2025 Order”), a development consent order under the Planning Act 2008 (“the Act”).
This Order follows an applications under paragraph 2 of Schedule 6 to the Act for a non-material change to the 2025 Order. The amendment varies the commitment in the register of environmental actions and commitments contained in the Code of Construction Practice, which provides for mitigation relating to the in-combination air quality effects on Epping Forest Special Area of Conservation along part of the M25.
This non-statutory note clarifies that the legislation modifies the existing 2025 DCO made under the Planning Act 2008.
The modification stems from an application considered a non-material change to the original consent documents.